Inductive receivers for electrical devices

ABSTRACT

A power providing system for an electrical device includes a secondary inductor, wired to the electrical device, for inductively coupling with a primary inductor hardwired to a power supply. The secondary inductor is incorporated into an accessory of the electrical device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of PCT application Ser. No.PCT/IL2008/001348 filed Oct. 12, 2008, which claims the benefit of U.S.provisional application Ser. Nos. 60/960,635 filed Oct. 9, 2007;60/960,878 filed Oct. 18, 2007; 61/006,131 filed Dec. 26, 2007 and61/064,403 filed Mar. 4, 2008, which are hereby incorporated byreference in their entirety.

TECHNICAL FIELD

The present disclosure is directed to providing power to electricaldevices using portable electrical devices adapted to receive powerinductively.

BACKGROUND

Mobile communication devices, such as computers, cellular telephones andthe like, are typically powered by power cells, i.e. rechargeableelectrochemical cells often also referred to as batteries. In order torecharge the power cells such devices are generally provided with acharger unit for connecting to a power jack socket on the device whichis wired to contacts with the terminals of the cells. The charger itselfusually consists of a plug box containing a step-down transformer and anAC-DC converter or rectifier which is wired to a connecting plug. Whenin use, the plug box is plugged into a 120V or 240V mains socket and theconnecting plug is coupled to the device. The wire trailing between thedevice and the plug box can be unsightly. Moreover, if the trailing wireis snagged or jerked the wire and connectors may be damaged, as indeedcould be the socket or the wall. Furthermore, the device may be pulledto the ground.

Chargers are bulky items to carry around. Therefore most users ofcompact portable equipment such as cell phones and the like do not carrychargers with them, but prefer to rely upon periodic charging, perhapsover night. Often users rely on even more infrequent charging. As aresult cells often run down at inconvenient times when no charger isavailable.

Inductive battery charger systems are known such as the system describedin U.S. Pat. No. 7,164,255 to Hui incorporated herein by reference. InHui's system a planar inductive battery charging system is designed toenable electronic devices to be recharged. The system includes a planarcharging module having a charging surface on which a device to berecharged is placed. Within the charging module, and parallel to thecharging surface, is at least one, and preferably an array of primarywindings that couple energy inductively to a secondary winding withinthe device to be recharged. The disclosure also provides secondarymodules that allow the system to be used with conventional electronicdevices not formed with secondary windings.

Hui's system provides an inductive charging platform for mobiletelephones. However, unless the device to be charged has an integralsecondary winding coil, it may be necessary to carry a bulky secondarymodule with which to use the platform. Hui's system does not describeany convenient means for providing secondary windings for conventionaldevices.

There is therefore a need for a convenient power supply for a mobilecommunication device and particularly for a charger, which may beconveniently retrofitted to conventional devices.

SUMMARY

It is an aim of the disclosure to provide an inductive power providingsystem for an electrical device.

In accordance with a first embodiment, the present disclosure isdirected to providing a power providing system for an electrical devicecomprising: a secondary inductor, wired to the electrical device, forinductively coupling with a primary inductor hardwired to a powersupply, wherein the secondary inductor is incorporated into an accessoryof the electrical device.

In various embodiments the electrical device may be selected from thegroup comprising: computers, mobile telephones, media players, PDAs,Walkman®s, portable CD players, dictaphones, portable DVD players andmobile communications devices. The accessory may be selected from thegroup comprising: removable casings of the electrical device, carryingcases for transporting the electrical device, straps for carrying theelectrical device, carrying handles, fashion-tags, ornamental pendants,mobile danglers, skins for encasing the electrical device, stickers foradhering to the electrical device, belt-clips, neck support straps andearphone units.

Optionally, the secondary inductor comprises an electrical connector forcoupling to a power jack socket such that the secondary inductor isretrofittable to the electrical device. In one embodiment, theelectrical connector comprises a male plug portion, for coupling withthe power jack socket and a female socket portion for coupling to anexternal power source.

In some embodiments the electrical device comprises a removable powerpack; the power pack being connectable to the electrical device viacontacts, the secondary inductor comprising an electrical connector forcoupling to the contacts. The electrical device may further comprise anelectrochemical cell, and the secondary inductor may be connected to theelectrochemical cell via a rectifier for charging the electrochemicalcell.

Optionally, the accessory comprises a USB plug for coupling to acomputer such that the electrochemical cell is selectably chargeable bypower drawn from the computer. Typically, the USB plug is wired to adata jack socket of the electrical device such that data is exchangeablebetween the computer and the mobile communication device.

In various embodiments, the power providing system further comprises anaudio device having an external earphone unit, wherein the secondaryinductor is incorporated into the earphone unit. Typically, the externalearphone unit, comprises at least one inductive element for inductivelycoupling the primary inductor to the secondary inductor. Optionally, theinductive element comprising the secondary inductor. The secondaryinductor may comprise a voice coil of at least one speaker of theearphone unit. Alternatively, the secondary inductor comprises at leastone loop of wire. The loop of wire may be incorporated into a necksupport strap for supporting the audio device. Alternatively, the endsof at least one wire are connected together to produce the at least oneloop of wire. In other embodiments of the disclosure the earphone unitincludes an inductive element which comprises a ferromagnetic coreextending through the secondary inductor and into the earphone unit forselectively coupling with the primary inductor.

In still another embodiment of the disclosure, the power providingsystem comprises at least one inductive coil, the inductive coil beingselectively connectable to: at least one charging circuit for connectingthe inductive coil to a power pack via a rectifier for charging thepower pack when the secondary inductor is inductively coupled to theprimary inductor; and at least one driving circuit connectable to thepower pack for providing a varying electrical potential to the inductivecoil such that the inductive coil transfers power to an externalinductor wired to an external electrical load. In various embodiments,the power pack is selected from the group comprising: nickel-cadmiumcells, nickel metal hydride cells, alkaline cells, flow batteries,rechargeable electrochemical cells and capacitors. Optionally, the powerproviding system comprising a ferromagnetic core for guiding magneticflux through the inductive coil when inductively coupled. Typically, thedriver comprises at least one switching unit for intermittentlyconnecting the power pack to the inductive coil at high frequency.

Optionally, the power providing system additionally comprises a jack forconductively connecting the power pack to an external power source forcharging purposes. The power providing system may additionally comprisea jack for conductively connecting the power pack to the externalelectrical load.

It is a further aim of the disclosure to provide a computer comprisingan inductive coil which is selectively connectable to: at least onecharging circuit for connecting the inductive coil to a power pack via arectifier for charging the power pack when the secondary inductor isinductively coupled to the primary inductor; and at least one drivingcircuit connectable to the power pack for providing a varying electricalpotential to the inductive coil such that the inductive coil transferspower to an external inductor wired to an external electrical load. Inone embodiment, the power pack is configured to power the computer.

It is a further aim of the disclosure to provide an inductive chargercomprising at least one inductive coil and at least one chargeable powerpack, the charger additionally comprising: at least one charging circuitfor connecting the inductive coil to the power pack when the inductivecoil is inductively coupled to a primary coil wired to a power supplyfor charging the power pack; and at least one driving circuitconnectable to the power pack for providing a varying electricalpotential to the inductive coil such that the inductive coil isinductively couplable to a secondary coil wired to an electrical load.

BRIEF DESCRIPTION OF THE FIGURES

For a better understanding of the disclosure and to show how it may becarried into effect, reference will now be made, purely by way ofexample, to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of the various embodiments of the presentdisclosure only, and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of the disclosure. In this regard, noattempt is made to show structural details of the disclosure in moredetail than is necessary for a fundamental understanding of thedisclosure; the description taken with the drawings making apparent tothose skilled in the art how the several forms of the disclosure may beembodied in practice. In the accompanying drawings:

FIG. 1 is a schematic illustration of an inductive power providing meansfor powering a computer, in accordance with one embodiment of thepresent disclosure;

FIG. 2 is a schematic illustration of a computer provided with asecondary inductive coil incorporated within the base thereof, forinductively powering the computer by bringing into proximity with apower supplying inductive coil, according to another embodiment of thedisclosure;

FIG. 3 shows the jack sockets of a portable computer according to afurther embodiment of the disclosure for coupling to an electricitymains power source via an inductive couple or via a conventional powersupply;

FIG. 4 is a schematic illustration of a computer carrying case accordingto another embodiment of the disclosure with an inductive power coilbuilt into the base thereof;

FIG. 5 is a schematic illustration of another embodiment of the computercarrying case having an inductive power coil built into the handlethereof;

FIG. 6 is a schematic illustration of still another embodiment of thecomputer carrying case having an inductive power coil built into theshoulder strap thereof;

FIGS. 7 a and 7 b are schematic illustrations of a retrofittablecarrying handle for a portable computer with a built-in inductive powercoil according to further embodiments of the disclosure;

FIG. 8 is a schematic illustration of a fashion-tag attachment with abuilt-in inductive power coil in accordance with still anotherembodiment of the disclosure;

FIGS. 9 a and 9 b are schematic illustrations of a computer providedwith another embodiment of the disclosure including a retractablesecondary inductive coil attachment;

FIG. 10 is a schematic illustration of an inductive charger for a mobilecommunication device of a further embodiment of the disclosure;

FIGS. 11 a and 11 b are schematic illustrations of a mobilecommunication device with an inductive charger built into the skinthereof according to another embodiment of the disclosure;

FIG. 12 a is a schematic illustration of a self-adhesive inductivecharger for a mobile communication device adhered to a power cellaccording to another embodiment of the disclosure;

FIG. 12 b is a schematic illustration of how the self-adhesive inductivecharger of FIG. 12 a may be used to charge cells;

FIG. 13 is a schematic illustration of an inductive charger of anotherembodiment of the disclosure having a hermaphrodite power connector;

FIGS. 14 a-c are schematic illustrations of a protective case accordingto a further embodiment of the disclosure with a built-in an inductivecharger for a mobile communication device;

FIG. 15 is a schematic illustration of a mobile communication devicewith an inductive charger built into a fashion tag;

FIG. 16 is a schematic illustration of an inductive charger for a mobilecommunication device with a combined data connector;

FIG. 17 is a block diagram showing the main elements of a charger for anaudio device incorporated into an earphone unit in accordance withanother embodiment of the disclosure;

FIG. 18 a is a schematic diagram of a charger for an audio deviceaccording to another embodiment of the disclosure, wherein the voicecoil of a speaker is wired to the power cell of the audio device and isinductively coupleable to a primary inductor;

FIG. 18 b is a block diagram showing the main elements of a switchingunit for connecting the charger of FIG. 18 a to an audio device;

FIG. 19 a is a schematic diagram of another embodiment of thecharger foran audio device wherein an induction loop is incorporated into a necksupport of the earphone unit;

FIG. 19 b is a schematic diagram of still another embodiment of thecharger for an audio device wherein an induction loop is formed byconnecting contact-terminals incorporated into the earphone cables;

FIG. 19 c is a schematic representation of an embodiment of the chargerfor an audio device wherein an inductive core extends through aninternal secondary coil and into the earphone unit for coupling with anexternal primary inductor;

FIG. 20 is a flowchart showing a possible method for charging theinternal power cell of an audio device;

FIGS. 21 a and 21 b are block diagrams schematically representing aninductive charger according a further embodiment of the disclosure incharging and driving modes respectively;

FIG. 22 a is a schematic representation of another embodiment of theinductive charger being charged by a primary coil;

FIG. 22 b is a schematic representation of the inductive charger of FIG.22 a being used to charge a mobile telephone wired to a secondary coil;

FIG. 23 a is a schematic representation of a mobile computer beingpowered by a primary coil via an integral inductive coil according toanother embodiment of the disclosure, and

FIG. 23 b is a schematic representation of a mobile telephone beingcharged by the inductive coil of FIG. 23 a.

DETAILED DESCRIPTION

As those of ordinary skill in the art will understand, various featuresof the present disclosure as illustrated and described with reference toany one of the Figures may be combined with features illustrated in oneor more other Figures to produce embodiments of the present disclosurethat are not explicitly illustrated or described. The combinations offeatures illustrated provide representative embodiments for typicalapplications. However, various combinations and modifications of thefeatures consistent with the teachings of the present disclosure may bedesired for particular applications or implementations.

Reference is now made to FIG. 1, showing a power providing means 10 fora portable computer 12 consisting of a secondary inductor 14 wired tothe portable computer by a connecting wire 15 that is typically a twostripe multi-fiber insulated wire, such as used for providing power toportable computers via a transformer.

The secondary inductor 14 is essentially a coil which can be broughtinto proximity with a primary inductor 16 which is essentially anothercoil hardwired to a mains power supply 18. The primary coil 16 andsecondary coil 14 thus form an inductive power couple 20, allowing powerto be provided to the portable computer 12. The primary coil 16 may besituated in the table top 18 of a conference table, for example. Bysupplying power inductively in this manner, trailing wires may beavoided, providing a neater, safer and more flexible work environment.

It will be appreciated that, although a system for providing power to aportable computer is described herein, the power providing means 10 mayalso be applicable to the provision of power to other electrical devicessuch as a desktop computer, handheld computer, vehicle mounted computeror the like. Power providing means 10 may also be used by other portablesystems such as hand-held DVD players, projectors, hand-heldtelevisions, digital picture frames or sound systems for example.

As shown in FIG. 2, in an embodiment of the disclosure, the secondarycoil 14 may be integral to the portable computer 12, being built intothe base thereof, under the keyboard. Positioning the computer 12 over aprimary coil 16 a in a work-surface 22, for example, enables power to beprovided thereto, without trailing wires. The power may be used torecharge the electrochemical power pack (battery) 24 or to power theportable computer 12.

As shown in FIG. 3, in another embodiment of the disclosure, thesecondary coil 14 a may be coupled to a portable computer 12 designedfor optional power provision in this manner, via a jack 26 that isplugged into a dedicated jack socket 28 designed for coupling thesecondary coil 14 a. The dedicated jack socket 28 is separate from thepower supply jack socket 30 supplied for coupling to a power supply (notshown) of the type consisting of a transformer for plugging into a powermains socket that is typically provided. The dedicated jack plug 26 andjack socket 28 may usefully be physically different from power supplyjack socket 30 and jack plug (not shown), to prevent misconnection.Similarly, the inductive and transformer sockets 28, 30 may beappropriately labeled, perhaps with letters I and T for inductive andtransformer, to prevent confusion.

However, since the purpose of inductive coupling is to avoid and replacetransformer coupling, in various embodiments, the secondary coil 14 a isconnected to the portable computer 12 via the power jack socket 30designed for coupling to a mains via a power supply of the transformertype. In this manner, existing portable computers may be retrofittedwith a secondary coil 14 a for inductive powering.

Power may alternatively be provided to the portable computer 12 viaconnecting points designed for coupling to a rechargeableelectrochemical power pack within the housing for the power pack.

The secondary coil 14 a may be provided as a sort of puck on a wire thatcan be positioned over an access point in a surface where a primary coil16 is provided.

Alternatively however, usefully, to provide a neat solution, toeliminate trailing wires, recoiling such wires and to make disconnectingsimpler, as shown in FIG. 4 the secondary coil 14 b may be incorporatedinto an accessory that has additional functionality. For example, it maybe built into the side of a carrying case 40 or skin provided forcarrying the portable computer 12. In one embodiment as shown in FIG. 5the secondary coil 14 c is built into the handle 42 of a carrying case44.

As shown in FIG. 6, in one embodiment, the secondary coil 14 d is builtinto the shoulder strap 46 of a carrying case 48 which being flexible,gives more flexibility to the user, in that the computer 12 can be leftin its case, and situated anywhere within a radius of about 80 cm from a“power-spot” where a primary coil 16 is situated.

With reference now to FIGS. 7 a and 7 b, a retrofittable carrying handle52 for a computer 12 is shown. The handle 52 is attached to the computerby straps 54 and incorporates a built-in inductive power coil 14 eelectrically coupled to the computer via a power plug 56 which plugsinto the power jack 30 of the computer 12.

Whilst the computer 12 is being carried, the straps 54 surround andsupport the computer 12 as shown in FIG. 7 b. However, as shown in FIG.7 a, when the computer 12 is laid down and in use, the support straps 54are opened allowing the inductive power coil 14 e to be coupled to aprimary coil 16 situated anywhere within their radius.

Alternatively, with reference to FIG. 8, the inductive power coil 14 maybe concealed inside a fashion-tag 62 attached to the computer 12 forexample by a connecting chain 64 or the like. Thus, by aligning thefashion-tag 62 to a power spot, the computer may draw power from aprimary coil 16.

In a further embodiment, a retractable secondary inductive coilattachment 70 may be retrofitted to a portable computer 12, as shown inFIGS. 9 a and 9 b. The secondary inductive coil 14 f is held in a tongue74 mounted upon the base of the computer 12 and when the computer 12 isin use as shown in FIG. 9 a, the tongue 74 may be extended so that thesecondary coil 14 f may couple with a power spot 16 within its radius.

When the portable computer is stowed, as in FIG. 9 b, tongue 74 may beretracted. In one embodiment, the thickness of the secondary inductivecoil attachment 70 is less than the height of the feet 13 of thecomputer 12 so that the attachment 70 does not prevent the computer 12lying flat along a table top.

Referring now to FIG. 10, an inductive charger 100 is shown for chargingthe power cells of a mobile communication device 200 such as mobiletelephone, personal digital assistant (PDA), camera or the like, indeedmany mobile devices include all of these functions. The charger 100consists of a secondary coil 120 wired to the mobile communicationdevice 200 typically via a power jack socket 220 of by a connecting wire140—typically a two stripe multi-fiber insulating wire, such as used forelectrically connecting a power source to a mobile communication devicevia a transformer.

The secondary coil 120 can be brought into proximity with a primary coil10 hardwired to a mains power supply, to form an inductive power couple,allowing power to be provided to recharge the cells 240 (FIGS. 12 a and12 b) of the mobile communication device 200. The primary coil 10 may besituated in the table top 20 of a conference table, for example, therebyallowing a phone 200 to be recharged thereby. By inductively rechargingin this manner, trailing wires may be avoided or at least minimized. Thesecondary coil 120 may be provided for example as a sort of puck 122 ona wire that can be positioned over an access point in a surface where aprimary coil 10 is provided. Alternatively the secondary coil 120 may bebuilt into an accessory of the telephone 200.

Over the years, mobile telephones have become a fashion item and variousfashionable accessories are often sold for use therewith. Suchaccessories include for example, replacement phone skins, protectivecases, belt clips, small ornamental pendants, sometimes known as “mobiledanglers” and the like. Some such accessories are merely decorative,others perform secondary functions such as providing added protection tothe device, or more convenient ways to carry the device. The secondarycoil 120 of the current disclosure may be incorporated into any ofthese.

As shown in FIG. 11 a, according an embodiment of the disclosure thesecondary coil 120 may be built into the skin or casing 260 a, 260 b ofthe mobile communication device. Positioning the mobile communicationdevice over a primary coil 10, as shown in FIG. 11 b, at an access pointin a work-surface 20, for example, enables power to be provided to thecharger thereby charging the power cells 240 of the mobile communicationdevice 200 without trailing wires.

The charger may be connected directly to the terminals of the powercells. Alternatively the charger may be connected to the power cells viathe power jack socket 220 of the mobile communication device 200.

According to another embodiment, shown in FIG. 12 a, the secondary coil120 may be provided with an adhesive surface 122 so that the coil 120may be adhered directly onto the power cells 240 of a mobiletelecommunication device 200 in conductive contact with the terminals ofthe power cells. When power cells 240 are positioned such that thesecondary coil 120 forms as inductive couple with a primary coil 10 thecells 240 may be recharged. As shown in FIG. 12 b, it is noted that inthis embodiment, the cells 240 are recharged directly from the secondarycoil 120 so the cells 240 do not need to be connected to the device inorder for them to be charged.

Referring now to FIG. 13, in further embodiment, the secondary coil 120is wired to a hermaphrodite power connector 160 including both a maleplug 162 and a female socket 164. The male plug 162 of the hermaphroditepower connector 160 may be coupled to the power jack socket 220 of thedevice while still providing a female socket 164 for accommodating theplug 40 of a conventional conductive charger. With this embodiment, auser may select between charging the power cells 240 of the mobilecommunication device 200 using the inductive charger 100 or theconductive type charger. The selection may be facilitated by means of aswitch although, in one embodiment, the power connector 160 isconfigured automatically to select the inductive charger whenever thesecondary coil 120 is inductively coupled to a primary coil 10 and toselect the conductive power supply whenever the female socket 164 isconductively coupled to a power source.

Alternatively, in the embodiment shown in FIGS. 14 a-c, the secondarycoil 120 may be built into a protective or fashionable case 300 whichmay be fitted to a mobile communication device 200. The secondary coil120 is typically wired to a hermaphrodite power connector 160 within thecase 300 which is configured to couple with the power jack socket 220 ofthe mobile communication device.

A further embodiment is illustrated in FIG. 15 showing a mobilecommunication device 200 having a secondary coil concealed within afashionable tag 400, such as a so called “mobile dangler” or the like,which may be plugged directly into the power jack socket 220 withadditional mechanical support 420 optionally provided. The inductivecharger 100 of the disclosure may thus be incorporated within a fashionaccessory for the mobile communication device. In a similar manner, thesecondary coil 120 may be concealed in other accessories of the mobiletelecommunication device such as a belt clip, neck cord, hand strap orthe like.

According to still another embodiment, with reference to FIG. 16, aninductive charger 700 has a data channel coupled to the data jack socket280 of the mobile communication device 200. A USB (Universal Serial Bus)cable 720 leading to a USB plug is wired to the inductive charger whichmay be connected to USB jack socket 820 of a computer 800, for example,thereby providing a data link between the mobile communication device200 and the computer 800.

The USB connector 740 may, in addition, draw power from the computer 800and may thus be used to provide power to charge the power cells 120 ofthe mobile communication device 200 directly. As described hereinabovewith reference to the hermaphrodite connector, the charger 700 may beconfigured to select automatically between charging the power cells 120from the USB connector 740 or the secondary coil 120 depending upon theavailability of power.

U.S. Pat. No. 7,180,265 to Nokia Corporation, titled “Charging Devicewith an Induction Coil” describes an inductive charging device forcharging portable electronic devices with small footprints. The chargerdescribed in '265 includes a battery; a first induction coil coupled tothe battery; and an induction core extending through the first inductioncoil. The induction core has a portion which extends in an outwarddirection from the charging device and is adapted to removably couplewith a second induction coil of a portable electronic device byextending into the second induction coil.

The charger described in '265 is essentially a charging hook upon whichelectronic devices may be suspended by support loops. The hook iscoupled to the first inductive coil and is adapted to charge up theelectronic devices via the secondary inductive coils which may beincorporated into the support loops. '265 claims to provide a convenientway to organize devices being charged. However, for some applicationsthe support strap itself is undesirable, and as discussed hereinabove,there is a general desire to limit the number of wires, straps andcables.

By way of example, referring now to FIG. 17, a block diagram showing themain elements of an inductive charger 1100 for charging the internalpower cells 1220 of an audio device 1200, according to an embodiment ofthe disclosure.

The charger 1100 includes a secondary inductor 1140 wired to the powercells 1220 of the audio device 1200 via a rectifier 1240. An inductiveelement 1180 is incorporated into the earphone unit 1120 for inductivelycoupling the secondary inductor 1140 to an external primary inductor1320.

The primary inductor 1320 is typically wired to a power supply 1300 viaa driving unit 1310. The driving unit 1310 provides electronics to drivethe primary inductor 1320, such as a switching unit providing a highfrequency oscillating voltage supply, for example.

Charger 1100 is suitable for use with audio devices 1200 requiringearphones 1121 connected via earphone cables 1122 such as, telephones,media players, personal digital assistants (PDA), Walkman®s, portable CDplayers, portable DVD players, mobile communications devices and thelike.

It is a particular feature of this embodiment, that at least a part ofthe inductive charger 1100 is incorporated in the earphone unit 1120 ofthe audio device 1200. This represents an advantage over prior artdevices such as the system described in U.S. Pat. No. 7,164,255 to Hui,which disadvantageously requires a secondary winding to be incorporatedeither within the device itself or in a dedicated adaptor, whereas theinductive charger 1100 of the present disclosure is suitable for use incharging audio devices with small footprints. Furthermore, because theinductive charger 1100 of the present disclosure is incorporated intothe earphone unit 1120, the dimensions of the audio device 1200 itselfare not compromised by the addition of peripheral elements such as thesupport strap described in U.S. Pat. No. 7,180,265 to Nokia Corporation,for example.

With reference to FIG. 18 a, a schematic diagram of a charger 2100 foran audio device 2200 according to another embodiment is shown. In thisembodiment, the earphone unit 2120 includes a moving coil speaker 2122incorporated within an earpiece 2124 which is connected via a signalline 2125 to a plug 2126 for coupling to the audio device 2200 via anearphone jack 2202. The voice coil 2140 of the moving coil speaker 2122is a transducer that receives electrical signals from the signal lines2125 and converts them to audio signals.

The voice coil 2140 is additionally configured to be couplable to anexternal primary inductor 2320 which may be housed within a dockingstation 2322. Thus the voice coil 2140 may serve as the secondaryinductor 1140 (FIG. 17) of the inductive charger 2100, providing powerto the audio device via the signal lines 2125. Alternatively, dedicatedpower lines within the earphone unit 2120 may provide a conductiveconnection between the voice coil 2140 and the internal power cell 220of the audio device 200 via a rectifier 1240 (FIG. 17).

FIG. 18 b is a block diagram of the main elements of a switching unit2270 for connecting the charger 2100 of FIG. 18 a to an audio device2200. The switching unit 2270 is provided to selectively connect thevoice coil 2140 to the audio device 2200. The switching unit 2270 may bea separate unit that is retrofittable both to the audio device 2200 andto the earphone unit 2120. Alternatively, the switching unit 2270 may beincorporated into either the audio device 2200 or the earphone unit2120.

The switching unit 2270 may connect the voice coil terminal C to eitheran audio signal input A or to a charger output B of a switching circuit2272. The audio signal input A receives an audio signal 2250 from anamplifier 2260 which is communicated to the voice coil 2140. The chargeroutput B is connected to the power cell 2220 via a rectifier 2240 andmay be used for charging the power cell 2220 when the voice coil 2140 iscoupled to primary inductor 2320.

Optionally the switching circuit 2272 may be controlled by a frequencydetector 2274 which is configured and operable to detect high frequencyvoltage fluctuations along the signal line. High frequency voltagefluctuations are indicative that the voice coil 2140 is coupled to anactive primary inductor 2320. Therefore, when such high frequencyfluctuations are detected, the switching circuit 2272 may be connectedto the charger output B for charging the power cell 2220.

FIGS. 19 a-c are schematic diagrams showing various embodiments ofcharger 3100, 4100, 5100 for an audio device 3200, 4200, 5200. Withreference to FIG. 19 a, the earphone unit 3120 includes a neck support3122. Within the neck support 3122 is an induction loop 3140 ofconductive wire 3142 that is wound into a coil and connected to theinternal power cell 1220 (FIG. 17) of the audio device 3200 via arectifier 1240 (FIG. 17). The inductive loop 3140 is configured toinductively couple with an external primary inductor 320. The audiodevice 3200 may be conveniently stored by suspending the neck support3122 from a hook 3322.

In various embodiments, the hook 3322 is fabricated from a ferromagneticmaterial which extends through a primary coil 3320. When the necksupport 3122 is suspended from the hook 3322, the ferromagnetic materialforms a common inductive core 3180 between the primary coil 3320 and theinductive loop 3140 within the neck support 3122. The primary coil 3320and inductive loop 3140 thus form an inductive couple such that powermay be inductively transferred from the primary coil 3320 to theinductive loop 3140, thereby charging the power cells 1220 (FIG. 17) ofthe audio device 3200.

Optionally, the inductive couple may be improved by the inclusion of aferromagnetic element (not shown) and may be incorporated into the necksupport 3122 and configured so as to couple with the ferromagneticinductive core 3180 of the hook 3322 so as to complete a magneticcircuit.

Although the example of an inductive loop 3140 within a neck support3122 is described herein, it is noted that a secondary inductor may behoused in various other components of an earphone unit. For example asecondary induction coil may be housed in a dedicated unit within theearphone cable. Alternatively a secondary coil may be incorporated intoa microphone housing such as is commonly included in the earphone cableof a cellular telephone. Alternatively again a secondary coil may beincorporated into a cable stowage unit such as a spring loaded winder asis sometimes included with earphone units for convenient storage.

An alternative embodiment of the induction loop is schematicallyrepresented in FIG. 19 b, wherein a charger 4100 for an audio device4200 according to another embodiment of the current disclosure is shown.The earphone unit 4120 of this embodiment includes two earpieces 4122 a,4122 b, each connected to the audio device 4200 via its own earphonecable 4124 a, 4124 b. A bundle of induction wires 4140, embedded in theearphone cables 4124, is connected to the internal power cell 1220 (FIG.17) of the audio device 4200 via the rectifier 1240 (FIG. 17).Contact-terminals 4142 a and 4142 b at each end of the bundle ofinduction wires 4140, typically located near the earpieces 4122 a, 4122b, are configured to conductively couple the ends of the bundle ofinduction wires 4140 thereby forming an induction loop. The inductionloop may be coupled with an external primary coil (not shown) such thatpower may be inductively transferred from the primary coil to theinductive loop.

FIG. 19 c is a schematic representation of a charger 5100 for an audiodevice 5200 according to still another embodiment of the disclosure. Theaudio device 5200 incorporates an internal secondary coil 5140 connectedto the internal power cell 5220 via the rectifier 5240. An inductivecore 5180 extends through the internal secondary coil 5140 and into theearphone unit 5120 for coupling with a primary inductor 5320. Theprimary inductor may, for example, be incorporated into a hook (notshown) for suspending the audio device 5200.

FIG. 20 is a flowchart showing a method for inductively charging theinternal power cell of an audio device in accordance with one embodimentof the disclosure. The method comprises the steps of:

-   -   step (a) providing an inductive charger incorporated within the        earphone unit of the audio device, including a secondary        inductor connected to the power cell via a rectifier;    -   step (b) providing an external primary inductor connected to a        power source via a driver;    -   step (c) inductively coupling the secondary inductor of the        charger to the external primary inductor, and    -   step (d) providing a variable voltage to the primary inductor.

Reference is now made to FIGS. 21 a and 21 b which are block diagramsschematically representing the inductive charger 6100 for use withanother embodiment of the disclosure. The inductive charger 6100consists of an inductive coil 6120 and a chargeable power pack 6140which can be connected to each other via a charging circuit 6160 oralternatively via a driving circuit 6180. It is a particular feature ofthe current disclosure that the inductive charger 6100 may be switchedbetween two modes: (a) a charging mode as shown in FIG. 21 a, and (b) adriving mode, as shown in FIG. 21 b. A mode selector 6170 is used toselect between the two modes.

With particular reference to FIG. 21 a, representing the inductivecharger 6100 in charging mode, the inductive coil 6120 is coupled to anexternal primary inductive coil 6220 which is connected to a powersupply 6240 via a driving unit 6260. The mode selector 6170 isconfigured to connect the inductive coil 6120 to the power pack 6140 viathe charging circuit 6160.

In the charging mode, the external primary coil 6220 generates anoscillating magnetic field. The internal inductive coil 6120 is placedin the vicinity of the external primary coil 6220, thereby creating amagnetic flux linkage between the primary coil 6220 and the internalinductive coil 6120, by which power is transferred from the externalprimary coil 6220 to the internal inductive coil 6120. Typically, directcurrent is used to reverse the electrochemical reactions that result inpower supply from the power packs and the charging circuit 6160rectifies the alternating current generated in the inductive coil 6120thereby allowing the power pack 6140 to be recharged.

Referring now to FIG. 21 b, representing the inductive charger 6100 indriving mode, where the inductive coil 6120 is inductively coupled to anexternal secondary inductive coil 6320 which is wired to an electricload 6340. The mode selector 6170 is configured to connect the inductivecoil 6120 to the power pack 6140 via the driving circuit 6180. In thedriving mode the power supply 6140 provides power to the driver circuit6180 which provides a varying electrical potential to drive theinductive coil 6120. The driver circuit 6180 typically includes a highfrequency switching unit intermittently connecting the power pack 6140to the inductive coil 6120. The varying electrical potential across theinductive coil 6120 produces an oscillating magnetic field. Therefore,an external secondary coil 6320 which is brought into the vicinity ofthe inductive charger 6100 may inductively couple with the inductivecoil 6120. An electric load 6340 wired to the secondary coil 6320 maythereby draw power from the power pack 6140.

Many examples of rechargeable power packs are known and may be suitablefor use with various embodiments of the inductive charger 6100. Examplesof rechargeable electrochemical cells include nickel-cadmium cells,nickel metal hydride cells, alkaline cells, flow batteries and the like.Other power storage devices such as lead alkali accumulators, capacitorsand supercapacitors may also be charged by the inductive charger 6100.

Reference is now made to FIGS. 22 a and 22 b showing an exemplaryinductive charger 7100 according to another embodiment of thedisclosure. A housing 7110 contains an inductive coil 7120 which iswrapped around a ferromagnetic core 7122 and is connected to an internalpower pack 7140 via a control box 7130. The control box 7130 containsdriving circuitry for the driving mode, charging circuitry for thecharging mode and a mode selector (not shown). In alternativeembodiments (not shown), additional circuitry may be provided forcharging the power pack 7140 from the mains or other external powersource, such as solar power or the like, via a dedicated jack. Adedicated jack may also be provided for conductively connecting with andthe powering of an external electrical load.

FIG. 22 a shows the inductive charger 7100 being charged up by aninductive power outlet 7200 which consists of a primary coil 7220concealed behind a facing layer, such as Formica or wood veneer, of aplatform 7280 such as a desk-top, a kitchen work-top, a conference tableor a work bench for example. The primary coil 7220 is wired to a powersupply 7240 via a driving unit 7260 providing the electronics to drivethe primary coil 7120. Driving electronics may include a switching unitproviding a high frequency oscillating voltage supply, for example.

As inductive power outlets 7200 become more widespread, it is consideredlikely that devices may be hardwired to secondary coils, to draw theirpower inductively therefrom. In particular, mobile phones, media playersand the like which are generally connected to external chargers viaconnecting wires may be provided with internal charging circuitry thatincludes a secondary coil for inductively coupling to inductive poweroutlet 7200.

FIG. 22 b shows a mobile phone 7300 which has an integral secondaryinductive coil 7320 connected to its internal power source 7340 via arectifier (not shown). The mobile phone 7300 may be charged by placingit over an inductive power outlet 7200 such as shown in FIG. 22 a,thereby inductively coupling the secondary coil 7320 of the device withthe primary coil of the outlet 7200.

Where no inductive power outlet 7200 is available, the mobile phone maybe charged by placing it on top of the inductive charger 7100, as shownin FIG. 7 b. With the inductive charger 7100 set to driving mode, themobile phones secondary coil 7320 inductively couples with the internalinductive coil 7120 of the inductive charger 7100 and draws powertherefrom.

According to another embodiment of the inductive charger, shown in FIGS.23 a and 23 b, the inductive charger 8100 is incorporated into a mobilecomputer 8000. The mobile computer 8000 has a built-in inductive coil8120 for powering the computer from an inductive power outlet 8200, asshown in FIG. 23 a. Once coupled to a primary coil 8220, the inductivecoil 8120 may power the computer and/or charge the internal power pack8140 of the mobile computer.

The inductive coil 8120 of the computer 8000 may additionally be used tocharge an external device such as a mobile phone 8300 with an in-builtsecondary coil 8320, as shown in FIG. 8 b. A similar use is already madeof computers 8000 to charge external devices such as media players,mobile phones, mice, Bluetooth devices and the like, generally usingdedicated cables and via standard ports, such as their USB (universalserial bus) ports. One advantage of this is that no such dedicatedcables are needed.

It is noted that, apart from the mobile computer 8000 described herein,inductive chargers may be incorporated into other hosts, such aselectric cars, generators, emergency lights or the like for chargingelectrical devices thereby.

The scope of the present disclosure is defined by the appended claimsand includes both combinations and sub combinations of the variousfeatures described hereinabove as well as variations and modificationsthereof, which would occur to persons skilled in the art upon readingthe foregoing description. While the best mode has been described indetail, those familiar with the art will recognize various alternativedesigns and embodiments within the scope of the following claims. Whilevarious embodiments may have been described as providing advantages orbeing preferred over other embodiments with respect to one or moredesired characteristics, as one skilled in the art is aware, one or morecharacteristics may be compromised to achieve desired system attributes,which depend on the specific application and implementation. Theseattributes include, but are not limited to: cost, strength, durability,life cycle cost, marketability, appearance, packaging, size,serviceability, weight, manufacturability, ease of assembly, etc. Theembodiments discussed herein that are described as less desirable thanother embodiments or prior art implementations with respect to one ormore characteristics are not outside the scope of the disclosure and maybe desirable for particular applications.

In the claims, the word “comprise”, and variations thereof such as“comprises”, “comprising” and the like indicate that the componentslisted are included, but not generally to the exclusion of othercomponents.

1. A power providing system for an electrical device comprising: asecondary inductor, wired to said electrical device, for inductivelycoupling with a primary inductor hardwired to a power supply, whereinsaid secondary inductor is incorporated into an accessory of saidelectrical device; and wherein said secondary inductor comprises anelectrical connector for coupling to a power jack socket such that saidsecondary inductor is retrofittable to said electrical device.
 2. Thepower providing system of claim 1 wherein said electrical device isselected from a group consisting of: computers, mobile telephones, mediaplayers, PDAs, Walkman®s, portable CD players, dictaphones, portable DVDplayers and mobile communications devices.
 3. The power providing systemof claim 1 said electrical connector being a hermaphrodite connectorcomprising: a male plug portion, for coupling with said power jacksocket and a female socket portion for coupling to an external powersource.
 4. The power providing system of claim 1, wherein saidelectrical device comprises a removable power pack; said power packbeing connectable to said electrical device via contacts, said secondaryinductor comprising an electrical connector for coupling to saidcontacts.
 5. The power providing system of claim 1, said electricaldevice further comprising an electrochemical cell, wherein saidsecondary inductor is connected to said electrochemical cell via arectifier for charging said electrochemical cell.
 6. The power providingsystem of claim 1 wherein said accessory is selected from a groupconsisting of: removable casings of said electrical device, carryingcases for transporting said electrical device, straps for carrying saidelectrical device, carrying handles, fashion-tags, ornamental pendants,mobile danglers, skins for encasing said electrical device, stickers foradhering to said electrical device, belt-clips, neck support straps andearphone units.
 7. The power providing system of claim 1 said electricaldevice further comprising an electrochemical cell, wherein saidaccessory comprises a USB plug for coupling to a computer such that saidelectrochemical cell is selectably chargeable by power drawn from saidcomputer.
 8. The power providing system of claim 7 wherein said USB plugis wired to a data jack socket of said electrical device such that datais exchangeable between said computer and said mobile communicationdevice.
 9. The power providing system of claim 1 wherein said secondaryinductor comprises at least one inductive coil, said at least oneinductive coil being selectively connectable to: a. at least onecharging circuit for connecting said at least one inductive coil to apower pack via a rectifier for charging said power pack when saidsecondary inductor is inductively coupled to said primary inductor; andb. at least one driving circuit connectable to said power pack forproviding a varying electrical potential to said at least one inductivecoil such that said at least one inductive coil transfers power to anexternal inductor wired to an external electrical load.
 10. The powerproviding system of claim 9 wherein said power pack is selected from agroup consisting of: nickel-cadmium cells, nickel metal hydride cells,alkaline cells, flow batteries, rechargeable electrochemical cells andcapacitors.
 11. The power providing system of claim 9 additionallycomprising a ferromagnetic core for guiding magnetic flux through saidinductive coil when inductively coupled.
 12. The power providing systemof claim 9 wherein said driver comprises at least one switching unit forintermittently connecting said power pack to said inductive coil at highfrequency.
 13. The power providing system of claim 9 additionallycomprising a jack for conductively connecting said power pack to anexternal power source for charging purposes.
 14. The power providingsystem of claim 9 additionally comprising a jack for conductivelyconnecting said power pack to said external electrical load.
 15. Acomputer comprising the inductive coil of claim
 9. 16. The computer ofclaim 15, wherein said power pack powers said computer.